What are the causes of a tectonic earthquake?

Many of the several million earthquakes that happen in the world every year go undetected because they are in remote areas or have tiny magnitudes. read more

A volcanic earthquake is typically much smaller than a tectonic earthquake and results from tectonic forces that occur in conjunction with volcanic activity. A collapse earthquake is a small earthquake in underground caverns and mines that is caused by seismic waves produced by an explosion of rock on the Earth's surface. read more

Plate Tectonics, the Cause of Earthquakes The plates consist of an outer layer of the Earth, the lithosphere, which is cool enough to behave as a more or less rigid shell. Occasionally the hot asthenosphere of the Earth finds a weak place in the lithosphere to rise buoyantly as a plume, or hotspot. read more

The movement of tectonic plates causes earthquakes when two plates that are in contact with each other move in opposite directions and release built-up stress. For example, one plate may move north, while the other may move south. read more